[S390] s390: use memory_read_from_buffer()

Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/ipl.c

@@ -14,6 +14,7 @@
 #include <linux/delay.h>
 #include <linux/reboot.h>
 #include <linux/ctype.h>
+#include <linux/fs.h>
 #include <asm/ipl.h>
 #include <asm/smp.h>
 #include <asm/setup.h>
@@ -338,14 +339,8 @@ static struct kobj_attribute sys_ipl_device_attr =
 static ssize_t ipl_parameter_read(struct kobject *kobj, struct bin_attribute *attr,
 				  char *buf, loff_t off, size_t count)
 {
-	unsigned int size = IPL_PARMBLOCK_SIZE;
-
-	if (off > size)
-		return 0;
-	if (off + count > size)
-		count = size - off;
-	memcpy(buf, (void *)IPL_PARMBLOCK_START + off, count);
-	return count;
+	return memory_read_from_buffer(buf, count, &off, IPL_PARMBLOCK_START,
+					IPL_PARMBLOCK_SIZE);
 }
 
 static struct bin_attribute ipl_parameter_attr = {
@@ -363,12 +358,7 @@ static ssize_t ipl_scp_data_read(struct kobject *kobj, struct bin_attribute *att
 	unsigned int size = IPL_PARMBLOCK_START->ipl_info.fcp.scp_data_len;
 	void *scp_data = &IPL_PARMBLOCK_START->ipl_info.fcp.scp_data;
 
-	if (off > size)
-		return 0;
-	if (off + count > size)
-		count = size - off;
-	memcpy(buf, scp_data + off, count);
-	return count;
+	return memory_read_from_buffer(buf, count, &off, scp_data, size);
 }
 
 static struct bin_attribute ipl_scp_data_attr = {